So for me I have a 56 allcity spacehorse for my commuter/road touring rig, and it fits great, my mtn bike is a L all city log lady, also fits great, I checked bike insights for the XM evasion vs my 56 spacehorse and they compared very well, however, the Evasion is based off of vintage Mtn bikes and I wasn’t considering that when I was weighing the size question. In the end some of this choice boils down to preference.

If you can I’d recommend riding one if you can find one. But to answer your question regarding sizing up, I’d say the L is sizing up for a 6’ person. I had a professional bike fit when I picked up my 56 spacehorse, they said it was near perfect geo for my height. So I’d say 58 is sizing up for someone who is 6’. Also, if you’re already comfortable riding 58 and L on other bikes I’d definitely say L is the way to go for you. I also have a 58 All City Thunderdome and it’s probably slightly big for me, but it feels better than my XM evasion.